Blossom Wilt, Brown Rot
Very common plant disease that causes fruits to rot prematurely on the tree. Usually infects the fruit through wounds which could be caused by insects or mishandling. Brown rot can infect fruit after it has been removed from the tree and will carry on to decompose the fruit even in cold storage. Brown Rot can also cause the wilting of blossoms.
Soft brown patches appear on fruit, usually surrounding a wound. Small concentric rings of cotton-like small off-white pustules appear on the surface of the fruit. Eventually, the whole fruit will turn brown and shrivel. Fruit that is on the tree will not fall if infected which enables the spores to be in a prime position to infect other fruits.
Wounds on fruit
Brown soft patches on fruit
Concentric circles of off white pustules
Shriveling of fruit
Blossom wilting and falling.
Remove fruit that is infected. Be careful not to accidentally store an infected apple with healthy ones to reduce the risk of spread. Prune out any infected wood and remove any trees that are heavily infected and burn them.
There are no viable chemical treatments available.
Windblown or insect-borne spores enter the fruit through open wounds (or wounds made by the insect) and the spores germinate. The fungus spreads through the neighbouring tissues and produces white cottony pustules on the surface of the fruit in concentric circles emanating from the wound. The fungi can then infect the spur of the branch and cause a canker on the wood.
Avoid unnecessary damage to fruit in situ and in harvesting. Pest management to reduce possible wounds on fruit. There are some varieties that are resistant to the fungus but in heavy outbreaks in a crop, the resistance won't hold up.